Vacuum tube



Patented Mar. 19, 1929.. r

UNITED STATES PATENT FFlCfE.

SLUEL RUBEN; 0F NEW YORK, N. Y.

vacuum TUBE.

' Application led J une 3,

' anode in such relation that when, said control element is 'connected to a suitable source of potential, a controlling electrostatic field is produced between the control element and l/the plate` element, which acts upon the discharge, causing constriction or.- expansion thereof according to the potential variations in said source, and affects the surface conductivity or space 'charge adjacent the plate surface. 1 y

An .object of the invention is to attain vcertain new and importantadvantages inl tube operation, as by always utilizing the .l full value of the electron stream discharge to the anode. l. e v

There are two commonly known types of electron discharge tubes, one of which comprises a heated cathode and .an anode or tween a control element connected to a source of "variable potential to control or modulate the electron stream between the cooperating'electrodes by blocking or obstructl its path to a degree depending upon the magnitudeor signof the potential, causing variations inthe plate current. The other type of tube also has the cathode, ano`o`le"`and A plate elements, butthe control element is not interposed between the-cathode and anode, and the electron stream is controlled by a transverse electrical eld established by the potential impressed upon the controlling element, which serves to deflect or otherwise alter the course of the stream from its .nor- -mal path between thei cathode and anode. In such a 'tube the controlling transverse v lfieldvmust vbe directly inthe electrical'field of thedischarge between the cathode and anode: Y. v'The tube of my invention/ differs from those of the prior` art in that its operation is based upon theemploy'ment ofthe potential, applied to the control element to vary the repulsion between the electrons of the stream to control thmffectiveplate area,

plate element, having interposed therebe-` 1924. Serial N'o. 717,501.

and therefore, itsimpedance and the plate current flow. i

I have found that if the anode is so placed that its edge is parallel and closely adjacent to the cathode, the electron stream does not discharge chiefly to the edge, but is distributed over the adjoining plate surface,

as well, the area of distribution varying in ,proportion'to the space charge or the repulsion reaction between the electrons, as .determined by the stream density, due to the elec.

element .is so placed that when it is negatively charged as to the anode the electron stream is constricted, causing an increase in the electron repulsion reaction and therefore, an increase in the density of the limiting spacey charge, a decrease in the stream flow and in the area of stream' distribution, or effective plate area, towards Ithe cathode. These effects vary in degree 'according to the magnitude of the impressedpotential, andl the reverse efl'ectsoccur if the applied po'- tential is of the oppositepolarity. The 1m-y pedance of the tube is controlled in. this way. The control element mustv not be within the path of the discharge, and a plurality, of. y

control and anode about the cathode. l

,The effect of the transverse field so estabelements may be arranged rection fof' the How of the stream, but to trostatic or magnetic fields. 4The control change the areav over which the stream discharges, varying the anode impedance accordiii ly; whereas, in the prior art, in thosel tubes in which the control element is not located .between the cooperating electrodes, the effect ofl change of .potentialmof V,the control element is to divert the stream to a path transverse of the normal line of travel. For

the proper operation of this tube, the narrow surface or edge of the plate element must be arranged approximately parallel to and closely spaced from the cathode, so that` the vspace charge effect, due to the electrostatic field of the dense electron stream at the. edge of the plate causes the distribution of the eleetron'discharge over the surface of" A. tube constructed upon this principle is applicableto the usual vacuumy tube uses,

such as the detection and amplification of radio and audio frequency oscillations, and to the generation of sustained oscillations.

The underlying principles of the invention may bevbetter understood from an explanation of a concrete apparatus 'embodying I plan views ofthe elements of the tube, and

illustrate the discharge characteristics under the control ofdifferent potentials of the delector plate. Referring more particularly to the drawings, l represents the glass containerkand 2, 3 and 5 respectively` the anode,l control and cathode elements. rlhe cathode with outlet terminals at 8 and 9 is supported by 4. rl`he` terminals for the anode and control elements areA respectively l() land 7. ln Fig.- 4 the usual elements in' a receiving system are Jtace is reduced in a degree depending uponl conventionally represented. Fig. 5 indicates the electron stream discharge when control element 3 is not charged. When that element is negatively charged with respecttov anode element 2, the electron stream is constricted as shownin Fig. 6, while Fig. 7 shows the Wide dischargedistribution when the control element is positively charged.'

When the device is operated with no charge upon the control element there is no transverse electrostatic field between the coe operating electrodes, and the electron stream between the cathode and the anode is distributed generally as indicated in Fig. 5, over the' surface of anode 2, permitting a constant plate current flow. But when a.

potential is applied to control element 3 and anode 2, as bythe impression of oscillations from the antenna, a transverse electrostatic field is established in the path of the elec-v tron stream; if negatively charged with respect to the anode, the electron stream is constricted as shown in Fig. 6 and the distribution of the stream along -the anode surthe magnitude of the potential diderence between the two elements, the density of the ieldincreasing the electron repulsion reaction, and thereby decreasing the effective plate area, and decreasing the plate current.

surface of the anode,

lf the controliele'ment is positively charged with respect to the anode the repulsion reaction decreases, and there is a vvider dis- A tribution of' the electron stream, a lower plate impedanceand an increased plate` current ilow.- When employed in a detector circuit, as shown in Fig. Ll, With a grid condenser,l there is a unilateral effect of grid charging, `and an increased rectification due to a better asymmetrical variation of the electron stream.

ldhat l claim is 1. An electron discharge device comprising ya container having mounted therewithinan electron emission element land in the plane of and edgewise to said element, a co-operating ano'de element consisting of' aV plurality ofl plates, and a control element located outlemitting element and a co-operating anode coinprisina plurality of plates in the plane ot and edgewise to, said electron emitting element comprising a pliielectrode, and means for varying the area,`

of impact of the electron stream upon the comprising a controleleinent having a plurality of plates adjacent to and parallel with said anode plates. y

4. An electron discharge device having therewithin an anode composed of plates,y an electron emission filament mountedfbetween and parallel with edges oi the plates of said anode, and a control element having lates equidistant from and parallel` witha plate of the anode.

5.V An electron discharge device having a,

filament cathode and a co-operating anode having two plates, said filament and platesv.being all in a common element having plates equidistant from and parallel with a plate of the anode. v t p 6. An electron discharge device having a filament cathode, ka co-operating anode com-` prising a pair of plates upon opposite sides of and in a plane with-the -lament, and a control element having a., pair of plates parallel with each late of the anode.

. Signed at New ork city in the county of plane,-and a control New York and State of 'New York this 2nd' day ofJune, A. D. 1924. SA

l L RUBEN. y 

